supercritical co2 cycle
TRANSCRIPT
Centrum výzkumu Řež s.r.o.
SUPERCRITICAL CO2 CYCLE
Václav Dostál
Outline
S-CO2 cycles overview
Aspects of S-CO2 cycles
Applications of S-CO2 cycles
R&D needs
Supercritical Cycles - What are they?
Thermodynamic cycles that take advantage of the changes of
properties around the critical point
2 major types
supercritical steam cycle - heating above critical pressure increases
temperature of heat addition
supercritical CO2 cycle - compression near the critical point reduces
compressor work (i.e. reduction of temperature of heat rejection)
Reduction of Compressor Work
Turbine Size
Steam turbine: 55 stages / 250 MW
Mitsubishi Heavy Industries Ltd., Japan (with casing)
Helium turbine: 17 stages / 333 MW (167 MWe)
X.L.Yan, L.M. Lidsky (MIT) (without casing)
Supercritical CO2 turbine: 4 stages / 450 MW (300 MWe)
(without casing)
1 m
Comparison of S-CO2 and Helium Cycles
Disadvantage of Supercritical CO2 cycle
- High Recuperation Heat
RECUPERATED HEAT
TOTAL HEAT
ADDED HEAT
POWER
OUTPUT
REJECTED
HEAT
RECUPERATED HEAT
TOTAL HEAT
POWER OUTPUT
ADDED HEAT
REJECTEDHEAT
HELIUM
CO2
QrCO2/QrHe ~ 2-3 => ~ 4 times bigger recuperators
Pinch-point in Recuperator
0
50
100
150
200
250
300
350
400
450
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Fraction of transferred heat
Te
mp
era
ture
(oC
)
0
10
20
30
40
50
60
70
80
Tem
pe
ratu
re D
iffe
ren
ce (o
C)
Low-pressure CO2
High-pressure CO2
Temperature Difference
Pinch-point location
Re-Compression Cycle
Advanced Reactors
SMRs
Waste Heat Recovery
Geothermal
Solar - CSP
Storage
Propulsion
An investigation of the supercritical CO2 cycle (Feher cycle) for shipboard application
Author: Combs, Osie V
150 kWe Military Unit
Hydrogen Production
Nuclear Energy Options for Hydrogen Production
B. Yildiz, M. S. Kazimi
Space
Mars Surface Power System
Sufficient power for all surface applications (i.e. ISRU,
habitat etc.) Satisfy NASA DRM.
~200 kWe
Develop long lasting Mars surface infrastructure
Lifetime of 25 EFPY
Economy
Competitors
Proven vs. new technology
Mass production
Uncertainty of power prices on the market
Opportunity or hurdle?
Proper selection of markets and applications
Commercialization Path
New trends in power engineering
Decentralization, small units
Power electronics/power conditioning
Small units as demos for large units
Turbomachinery type
Radial vs. Axial
Compressor development
Devil in details
Further Considerations
Maturity of technology
Heat exchangers
Compressors and turbines
Cycle control
Bearings
Lubricants
Seals
Valves
freezing
Conclusion
S-CO2 cycles are recently considered for many applications
Many companies are considering its application
Question is in what application they can be successfully applied
The cycle technology and components require substantial
development
For this development experimental loops are crucial
S-CO2 loop in CVR is by its design and possibilities well suited
for testing components, but also for experiments in the field of
thermodynamics and heat transfer
Projects like HeRo are very important for the cycle deployment
The COOL Application